METHOD FOR THE PURIFICATION OF ALPHA-ALUMINA FIBERS

摘要

The present invention relates to a method for the purification of ±-Al 2 O 3 whiskers previously obtained by vapor-liquid-solid deposition, under metal vapors-containing atmospheres. Said method involves the volatilization of metal impurities in controlled-atmosphere furnaces at the surface of the fibers and from the drops at the end of the fibers. The invention also relates to purified ±-Al 2 O 3 whiskers obtainable by a process as defined above and substantially free from metal impurities at the surface and at the end part of the fibers, as well as the use of the purified ±-Al 2 O 3 whiskers as defined above as fillers or reinforcement agents for the preparation of ceramic, metallic or polymeric composites.